Expandable Carton

ABSTRACT

A carton including a tubular structure defined by a top wall, a bottom wall, a first side wall, and a second side wall and a first end wall and a second end wall, each enclosing an open end of the tubular structure. The top wall includes a first chimney side panel and a second chimney side panel that are separable from one another. A first collapsible chimney end wall and a second collapsible chimney end wall, each being positioned adjacent one of the walls of carton, wherein the first chimney side panel, the second chimney side panel, the first collapsible chimney end wall, and the second collapsible chimney end wall can be raised to be substantially upright to form a chimney so as to expand the volume of the carton.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Applications Nos. 60/828,375, filed Oct. 5, 2006; 60/828,633, filed Oct. 7, 2006; and 60/829,473, filed Oct. 13, 2006.

TECHNICAL FIELD

This invention relates generally to cartons and, more specifically, to cartons that are expandable.

BACKGROUND OF THE INVENTION

Certain cartons are expandable or can otherwise be arranged to include an expanded open top, which is sometimes referred to as a chimney. The expanded open top increases the volume or capacity of the carton and allows a consumer to, for example, pour ice into the expanded open top and on top of the contents of the carton. Thus, these expandable cartons are sometimes referred to as ice-pack cartons. It is also desirable for such cartons to retain liquid that may accumulate in the bottom of the carton.

However, the expandable cartons found in the prior art are ill-suited for being erected, end-loaded, closed, and sealed in the same manner as a conventional end-loaded carton. Specifically, certain blank configurations found in the prior art require precise handling since expansion features of the blank are required to be formed at the same time as when ends of the blank are secured to one another to form a collapsed tubular structure. Other blank configurations found in the prior art require highly specialized machinery to form the end closure structures at open ends of a tubular structure that is formed from such a blank configuration.

In addition, there are other problems associated with certain expandable cartons found in the prior art. One such problem is that, when configured as an open-ended tubular structure, the features that allow the carton to expand can also interfere with articles that are loaded through the open ends. Another problem is that certain cartons require non-intuitive operations to erect the chimney.

Thus, a heretofore unaddressed need exists in the industry to provide a carton with a chimney feature that can be easily pre-formed as a collapsed tubular structure, that can be formed as an erected tubular structure and loaded by automatic packaging machinery, and that can be easily operated to erect a chimney feature.

SUMMARY OF THE INVENTION

The shortcomings of the prior art are overcome by an expandable carton with an expansion feature that is configured to form a chimney. The carton can be pre-formed (i.e. pre-folded and pre-glued) into a collapsed tubular structure by a carton pre-folding machine, which is sometimes referred to as in-plant equipment (IPE). Advantageously, the chimney is formed during the IPE phase such that the automatic packaging machine, sometimes referred to as out-plant equipment (OPE), does not have to be highly specialized so as to form the chimney during the OPE phase. Additionally, the chimney is formed in a step that is independent of the formation of the collapsed tubular structure by securing the end edges of the blank are secured together. Thus, the blank requires less precise handling on the IPE.

The exemplary embodiments described herein also provide a versatile blank that can be folded according to various methods so as to select the positions of collapsible end walls of the chimney. Accordingly, the positions of the collapsible end walls of the chimney can be selected so as not to obstruct end loading of the carton when configured as a tubular structure. The positions of the collapsible end walls, in combination with means for separating described herein, provide that the exemplary cartons include a chimney that is easy to erect.

Generally described, the carton includes a tubular structure defined by a top wall, a pair of side walls, and a bottom wall. The carton further includes end closure structures which define end walls at the opposite open ends of the tubular structure. The top wall is divisible into two chimney side panels and that can be erected to form side walls of the chimney. The chimney side panels can be separated by means for separating including, but not limited to, a tear strip, a severance line, combinations thereof and the like.

In the exemplary embodiments, a pair of collapsible chimney end walls is each hingedly connected to the top wall and to a respective end wall. Each collapsible chimney end wall includes a chimney end panel and chimney gusset panels that are folded and secured in a face contacting arrangement with one of the walls. In certain of the embodiments, means for separating the chimney side panels also separates adjacent chimney gusset panels. Once the chimney side panels are separated from one another and adjacent chimney gusset panels are separated from one another, the chimney side panels can be folded outwardly to form the side walls of the chimney and the collapsible chimney end walls unfold or expand to form the end walls of the chimney.

According to an exemplary embodiment, a blank for forming an expandable carton includes a top panel that includes a first chimney side panel and a second chimney side panel, which are separable from one another. The blank also includes a first panel group that is hingedly connected to the first chimney side panel along a first end edge of the top panel and a second panel group that is hingedly connected to the second chimney side panel along the first end edge of the top panel. The first panel group and the second panel group are configured to be folded and secured to form a collapsible chimney end wall without otherwise folding or securing the blank.

Each of the first panel group and the second panel group include a chimney gusset panel that is hingedly connected to a respective one of the first chimney side panel and the second chimney side panel; a chimney end panel that is hingedly connected to the chimney gusset panel; and a top end flap panel that is hingedly connected to the chimney end panel. The first panel group and the second panel group can be folded and secured to one another such that the top end flap panels form a composite top end flap; the chimney end panels form a composite chimney end panel; and the composite chimney end panel and the chimney gusset panels form the collapsible chimney end wall.

The blank further includes a first side panel that is hingedly connected to the top panel and a second side panel that is hingedly connected to a second side edge of the top panel. A first side end flap is hingedly connected to the first side panel and a second side end flap is hingedly connected to the second side panel. The first side end flap is adjacent to and separable from the first panel group and the second side end flap is adjacent to and separable from the second panel group. Since the panel groups are separable from the side end flaps, the panel groups can be folded and secured to one another as described above without necessitating additional folding of the blank.

The collapsible chimney end wall can be selectively positioned in a substantially face contacting arrangement to any one of the inside surface of a top wall of the carton, the outside surface of a top wall of the carton, and the outside surface of the end wall of the carton.

In certain embodiments, the blank further includes a removable tear strip that extends substantially across the top panel to secure the first chimney side panel to the second chimney side panel. In certain of these embodiments, the tear strip further secures the chimney gusset panels together.

According to an exemplary embodiment, a collapsed, end-loadable and expandable carton includes an open ended tubular structure formed from a plurality of panels that are hingedly connected one to the next. A first one of the plurality of panels includes a first chimney side panel and a second chimney side panel that are separable from one another. The first chimney side panel and the second chimney side panel, when separated, are foldable to provide the side walls of a chimney. The collapsed carton further includes a first collapsible chimney end wall and a second collapsible chimney end wall, each being hingedly connected to an opposite end edge of the first one of the plurality of panels. The collapsed carton also including a first composite top end flap that is hingedly connected to the first collapsible chimney end wall and a second composite top end flap that is hingedly connected to the second collapsible chimney end wall. The first composite top end flap and the second composite top end flap each extend outwardly with respect to an open end of the tubular structure.

The first collapsible chimney end wall and the second collapsible chimney end wall are selectively positionable to extend outwardly so as to be in a substantially face contacting arrangement with a respective one of the first top end flap and the second top end flap, or to extend inwardly so as to be in a substantially face contacting arrangement with the outside surface of the first one of the plurality of panels.

According to an exemplary embodiment, an expandable carton includes a tubular structure defined by a top wall, a bottom wall, a first side wall, and a second side wall. The top wall includes a first chimney side panel and a second chimney side panel that are separable from one another. The first chimney side panel is hingedly connected to the first side wall and the second chimney side panel is hingedly connected to the second side wall.

The expandable carton also includes a first end wall and a second end wall, each closing an open end of the tubular structure and a first collapsible chimney end wall and a second collapsible chimney end wall, each being positioned adjacent the outside surface of one of the walls of the carton. Each of the collapsible chimney end walls includes a chimney end panel hingedly connected to one of the first end wall and the second end wall and a first chimney gusset panel and a second chimney gusset panel that are separable from one another. Each of the chimney gusset panels connects the chimney end panel to a respective one of the first chimney side panel and the second chimney side panel.

The first chimney side panel, the second chimney side panel, the first collapsible chimney end wall, and the second collapsible chimney end wall are movable to respective raised positions to define a periphery of a chimney.

In certain embodiments, each of the first collapsible chimney end wall and the second collapsible chimney end wall is positioned adjacent the outside surface of the top wall. In alternative embodiments, the first collapsible chimney end wall is positioned adjacent the outside surface of the first end wall and the second collapsible chimney end wall is positioned adjacent the outside surface of the second end wall.

According to exemplary embodiments, the first chimney side panel and the second chimney side panel are separable by a tear strip. In certain of these embodiments, the first chimney gusset panel and the second chimney gusset panel are separable from one another by the tear strip. The removal of the tear strip separates the first chimney side panel from the second chimney side panel and separates the first chimney gusset panel from the second chimney gusset panel. In still other embodiments, the tear strip includes an end tab at each of its ends. Each end tab is secured to a respective one of the end walls to secure the first collapsible chimney end wall in a substantially face contacting arrangement to the first end wall and to secure the second collapsible chimney end wall in a substantially face contacting arrangement to the second end wall.

The foregoing has broadly outlined some of the aspects and features of the present invention, which should be construed to be merely illustrative of various potential applications of the invention. Other beneficial results can be obtained by applying the disclosed information in a different manner or by combining various aspects of the disclosed embodiments. Accordingly, other aspects and a more comprehensive understanding of the invention may be obtained by referring to the detailed description of the exemplary embodiments taken in conjunction with the accompanying drawings, in addition to the scope of the invention defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a blank for forming an expandable carton, according to a first exemplary embodiment of the present invention.

FIGS. 2-4 are plan views of the blank of FIG. 1 that illustrate steps of an exemplary method of forming a collapsed tubular structure.

FIG. 5 is a perspective view of an erected tubular structure formed from the blank of FIG. 1.

FIG. 6 is a perspective view of a carton formed from the blank of FIG. 1.

FIGS. 7 and 8 are perspective views of the carton of FIG. 6 that illustrate steps of an exemplary method of forming a chimney.

FIG. 9 is a plan view of a blank for forming an expandable carton, according to a second exemplary embodiment of the present invention.

FIGS. 10-12 are plan views of the blank of FIG. 9 that illustrate steps of an exemplary method of forming a collapsed tubular structure.

FIG. 13 is a perspective view of an erected tubular structure formed from the blank of FIG. 9.

FIGS. 14 and 15 are perspective views of a carton formed from the blank of FIG. 9 that illustrate steps of an exemplary method of forming a chimney.

FIG. 16 is a plan view of a blank for forming an expandable carton, according to a third exemplary embodiment of the present invention.

FIGS. 17-19 are plan views of the blank of FIG. 16 that illustrate steps of an exemplary method of forming a collapsed tubular structure.

FIG. 20 is a perspective view of an erected tubular structure formed from the blank of FIG. 16.

FIG. 21 is a perspective view of a carton formed from the blank of FIG. 16.

FIGS. 22 and 23 are perspective views of the carton of FIG. 21 that illustrate steps of an exemplary method of forming a chimney.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosed herein. It must be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms, and combinations thereof. As used herein, the word “exemplary” is used expansively to refer to embodiments that serve as illustrations, specimens, models, or patterns. The figures are not necessarily to scale and some features may be exaggerated or minimized to show details of particular components. In other instances, well-known components, systems, materials, or methods have not been described in detail in order to avoid obscuring the present invention. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

Referring now to the drawings, wherein like numerals indicate like elements throughout the several views, the drawings illustrate certain of the various aspects of exemplary embodiments of a carton. In the embodiments detailed herein, the term carton refers, for the non-limiting purpose of illustrating the various features of the invention, to a container for enclosing, carrying, and dispensing articles, such as beverage cans or bottles. However, it is contemplated that the teachings of the invention can be applied to other containers.

In each of the illustrated exemplary embodiments, a carton is formed from a blank, which is preferably a single sheet of suitable substrate. It is to be understood that, as used herein, the term “suitable substrate” includes all manner of foldable sheet material such as paperboard, corrugated board, cardboard, plastic, combinations thereof, and the like. Although in the illustrated embodiments a unitary blank is used to form a single carton, it should be recognized that two or more blanks may be employed to provide a single carton.

In the exemplary embodiments, the blanks form a carton for packaging an exemplary arrangement of exemplary articles. It is envisaged that the blanks can be sized or alternatively configured to form cartons for packaging other articles and/or different arrangements of articles.

As used herein, the term “fold line” refers to all manner of lines that define hinge features of the blank, facilitate folding portions of the blank with respect to one another, or otherwise indicate optimal panel folding locations for the blank. A fold line is typically a scored line, an embossed line, or a debossed line.

As used herein, the term “severance line” refers to all manner of lines that facilitate separating portions of the substrate from one another or that indicate optimal separation locations. Severance lines can be frangible or otherwise weakened lines, tear lines, cut lines, or slits.

It should be understood that severance lines and fold lines can each include elements that are formed in the substrate of the blank including perforations, a line of perforations, a line of short slits, a line of half-cuts, a single half-cut, a cut line, an interrupted cut line, slits, scores, any combination thereof, and the like. The elements can be dimensioned and arranged to provide the desired functionality. For example, a line of perforations can be dimensioned or designed with degrees of weakness to define a fold line and/or a severance line. The line of perforations can be designed to facilitate folding and resist breaking, to facilitate folding and facilitate breaking with more effort, or to facilitate breaking with little effort. For ease of distinguishing the lines of the blanks, fold lines are shown as dashed lines and severance lines are shown as solid or dot-dot-dashed lines.

A first exemplary embodiment of the present invention is illustrated in FIGS. 1-8. Referring to FIG. 1, a blank 100 includes a series of primary panels which define the walls of a tubular structure T. Specifically, the blank 100 includes first side panels 110, 118, a top panel 112, a second side panel 114, and a bottom panel 116. The primary panels are hingedly connected one to the next along substantially parallel fold lines. The first side panel 110 is hingedly connected to the top panel 112 along fold line 120, the top panel 112 is hingedly connected to the second side panel 114 along fold line 122, the second side panel 114 is hingedly connected to the bottom panel 116 along fold line 124, and the bottom panel 116 is hingedly connected to first side panel 118 along fold line 126.

The top panel 112 includes a tear strip Sa/Sb that extends between the opposite end edges E1, E2 of the top panel 112. The tear strip Sa/Sb is defined by severance lines 128 a, 128 b which are substantially parallel to the fold lines 120, 122. The portions of the top panel 112 that are on either side of the tear strip Sa/Sb are defined as chimney side panels P1, P2, which form the side walls of a chimney Y, as described in further detail below. In the illustrated embodiment, the tear strip Sa/Sb has two sections Sa, Sb that are separated by a severance line C. In alternative embodiments, the tear strip can be removed as a single section. Further, in alternative embodiments, the tear strip Sa/Sb can be substituted with a severance line or other means for separating the chimney side panels P1, P2.

End flaps or other panel groups are hingedly connected to opposite ends of each primary panel along fold lines. Certain of the end flaps and panels of the panel groups form end closure structures at respective open ends of the erected tubular structure T (shown in FIG. 5) and thereby define the end walls of an expandable carton 200 (shown in FIG. 6).

Continuing with FIG. 1, the blank 100 is substantially symmetric such that the end flaps or panel groups that are hingedly connected to opposite ends of each primary panel are substantially similar. Accordingly, the end closure structures of the carton 200 are substantially identical. Like references have been used to identify substantially similar elements. Each like reference includes a like numeral and, to distinguish like elements from one another, differing suffixes, such as “a” and “b,” have been affixed to elements identified by a like numeral. Generally, the description of one of like referenced elements is applicable to each of the other like referenced elements and, for clarity, only one of the like referenced elements is described unless a description of other or each of the like referenced elements is useful for understanding the invention.

First side end flaps 130 a, 138 a are hingedly connected to first side panels 110, 118 along fold lines 140 a, 148 a, respectively, a chimney end flap panel group 132 a is hingedly connected to top panel 112 along a fold line 142 a; a second side end flap 134 a is hingedly connected to second side panel 114 along a fold line 144 a; and a bottom end flap 136 a is hingedly connected to bottom panel 116 along a fold line 146 a. In the illustrated embodiment, the bottom end flap 136 a is dimensioned to cover the entire open end of the tubular structure T.

The chimney end flap panel group 132 a includes first and second panel groups 150 a, 152 a which are separable from one another along a severance line 154 a. The panels of the first and second panel groups 150 a, 152 a are configured such that they can be folded and secured to one another to provide a composite top end flap and a collapsible chimney end wall, as described in further detail below. The first and second panel groups 150 a, 152 a are substantially mirror images of one another with respect to severance line 154 a. The first panel group 150 a is hingedly connected to the first chimney side panel P1 along a first segment 142 a′ of the fold line 142 a and the second panel group 152 a is hingedly connected to the second chimney side panel P2 along a second segment 142 a″ of the fold line 142 a. It should be noted that the tear strip Sa/Sb extends between the fold lines 142 a, 142 b and is substantively aligned with the severance lines 154 a, 154 b such that the tear strip Sa/Sb and the severance lines 154 a, 154 b provide a substantially continuous line of separation across the blank 100.

Each of the first and second panel groups 150 a, 152 a includes a plurality of panels that are hingedly connected one to the next. The first panel group 150 a includes a first chimney gusset panel 160 a, a first chimney end panel 162 a, and a first top end flap panel 164 a. The second panel group 152 a includes a second chimney gusset panel 166 a, a second chimney end panel 168 a, and a second top end flap panel 170 a.

The chimney gusset panels 160 a, 166 a are separable from one another along the severance line 154 a. The first chimney gusset panel 160 a and the first chimney side panel P1 are hingedly connected to one another along the first segment 142 a′; the first chimney gusset panel 160 a and the first chimney end panel 162 a are hingedly connected to one another along a fold line 172 a; the first chimney end panel 162 a and the first top end flap panel 164 a are hingedly connected to one another along a fold line 174 a; and the first top end flap panel 164 a and the first side end flap 130 a are separable from one another along a severance line 176 a.

Similarly, the second chimney gusset panel 166 a and the second chimney side panel P2 are hingedly connected to one another along a segment of the fold line 142 a; the second chimney gusset panel 166 a and the second chimney end panel 168 a are hingedly connected to one another along a fold line 178 a; the second chimney end panel 168 a and the second top end flap panel 170 a are hingedly connected to one another along a fold line 180 a; and the second top end flap panel 170 a and the second side end flap 134 a are separable from one another along a severance line 182 a.

In the exemplary embodiment, the fold line 172 a is at an acute angle with respect to each of the fold lines 142 a, 174 a; the fold line 174 a is substantially perpendicular to the fold line fold line 142 a and substantially aligned with the fold line 120; and the severance line 176 a is at an acute angle with respect to each of the fold lines 140 a, 174 a. Similarly, the fold line 178 a is at an acute angle with respect to each of the fold lines 142 a, 180 a; the fold line 180 a is substantially perpendicular to the fold line 142 a and substantially aligned with the fold line 122; and the severance line 182 a is at an acute angle with respect to each of the fold lines 144 a, 180 a. In the exemplary embodiments, the acute angle is approximately forty five degrees. However, in alternative embodiments, it is contemplated that the fold lines and severance lines are at different angles with respect to one another.

In the first exemplary embodiment, a void V separates the chimney end panels 162 a, 168 a, the fold lines 172 a, 178 a extend convergingly from fold line 142 a to the void V, and the severance line 154 a extends from the fold line 142 a to the void V.

The bottom end flap 136 a is connected to the side end flaps 134 a, 138 a by bottom gusset panels 184 a, 186 a, respectively. The second side end flap 134 a and bottom gusset panel 184 a are hingedly connected along a fold line 190 a, bottom gusset panel 184 a and the bottom end flap 136 a are hingedly connected along a fold line 192 a, bottom gusset panel 186 a and the bottom end flap 136 a are hingedly connected along a fold line 194 a, and the first side end flap 138 a and bottom gusset panel 186 a are hingedly connected along a fold line 196 a.

The bottom end flap 136 a further includes a fold line 198 a that allows the outermost portion of the bottom end flap 136 a to fold outwardly when the blank 100 is formed as a tubular structure T, as described in further detail below.

Erecting the carton 200 from the blank 100 may be accomplished with the folding operations as described herein. The operations can be performed entirely or in part by automatic erecting machinery, or manually. The method of performing the erecting process is not limited to the exemplary method described. Particularly, the order of the steps can be altered according to manufacturing requirements, steps may be added or omitted, and the means for securing components to one another may vary. In addition, it is envisaged that each of the exemplary methods described herein can be used to form each of the exemplary blanks into a carton. The surfaces of sheet material may be secured together by suitable means for securing, such suitable securing means including tape, staples, interlocking folds, VELCRO@, glue or other adhesives, combinations thereof, and the like.

The various embodiments of the present invention provide, as one of many advantages, the ability to pre-fold and pre-glue the blanks into collapsed tubular structures that are suitable for shipping and storage. Specifically, an exemplary method of folding and securing a blank to form a collapsed tubular structure includes steps that form composite top end flaps and collapsible chimney end walls. By pre-forming these elements on in-plant equipment (IPE), the process to erect and load a tubular structure and to form end closure structures at open ends of the tubular structure to form a carton is simplified and easily accomplished with automatic packaging machinery, sometimes referred to as out-plant equipment (OPE).

Referring to FIG. 1, in the IPE phase of the first exemplary embodiment, the blank 100 is first formed as a collapsed tubular structure T. Adhesive, such as glue strip G, is applied near the outer edge of the inside surface of the first side panel 110 and near the outer edge of the inside surfaces of the first side end flaps 130 a, 130 b. Then, referring to FIGS. 1 and 2, the first side panel 118 is folded along the fold line 126 so that its inside surface is in a face contacting arrangement with the inside surface of the bottom panel 116. Additionally or alternatively, adhesive can be applied to the outside surface of the first side panel 118 (not shown). The top panel 112 along with the first side panel 110 are folded along the fold line 122 such that the inside surface of the top panel 112 is in a face contacting arrangement with the second side panel 114 and the first side panel 110 is in a face contacting arrangement with the inside surface of the bottom panel 116 and partially overlaps the first side panel 118. The adhesive that was previously applied to either or both of the first side panels 110, 118 is disposed between the overlapping portions thereby forming a composite first side panel 110/118 and composite first side end flaps 130 a/138 a, 130 b/138 b, with a seam M (FIG. 5) extending thereacross. At this point, the primary panels 110/118, 112, 114, 116 form the walls of a collapsed tubular structure T. The composite first side panel 110/118 defines a first side wall 210, the top panel 112 defines a top wall 212, the second side end panel 114 defines a second side wall 214, and the bottom panel 116 defines a bottom wall 216.

The IPE phase continues as the chimney end flap panel group 132 a is then folded and secured to form collapsible chimney end walls and composite top end flaps. It should be noted that the steps of the method for securing the walls of the tubular structure T together and the steps for forming the chimney features are distinct from one another or thus, need not be simultaneous. This is in part because the seam M does not extend across the chimney features. Consequently, the exemplary embodiments allow for more flexibility in the method used to form the chimney features, result in less bulky collapsed tubular structures, and require less precision to form the tubular structures. More specifically, the tubular structure T can be formed before, after, or at the same time the chimney features are formed.

Referring to FIG. 2, adhesive, represented by glue spots G, is applied to the outside surface of the top panel 112 directly onto, or on either side of, the tear strip Sa/Sb. Adhesive can additionally or alternatively be applied to the outside surfaces of the chimney gusset panels 160 a, 166 a. Thereafter, referring to FIGS. 2 and 3, the chimney end flap panel group 132 a is folded along the fold line 142 a such that the outside surfaces of the first and second chimney gusset panels 160 a, 166 a are in a face contacting arrangement with the outside surface of the top panel 112 with the adhesive detachably securing the first and second chimney gusset panels 160 a, 166 a to the top panel 112.

Turning now to FIGS. 3 and 4, the second chimney end panel 168 a along with the second top end flap panel 170 a is folded along the fold line 178 a such that the inside surface of the second chimney end panel 168 a is in a face contacting arrangement with the inside surface of the second chimney gusset panel 166 a. Adhesive, represented by glue strip G, is applied near an edge of the first chimney end panel 162 a and the first top end flap panel 164 a. The first chimney end panel 162 a along with the first top end flap panel 164 a is then folded along the fold line 172 a such that the chimney end panels 162 a, 168 a partially overlap and are secured to one another to define a composite chimney end panel 162 a/168 a; the top end flap panels 164 a, 170 a partially overlap and are secured to one another to form a composite top end flap 164 a/170 a; and the fold lines 174 a, 180 a substantially align with one another to define a composite fold line 174 a/180 a that hingedly connects the composite chimney end panel 162 a/168 a to the composite top end flap 164 a/170 a.

Referring to FIG. 4, a first collapsible chimney end wall X1 is simultaneously defined and includes the chimney gusset panels 160 a, 166 a and the composite chimney end panel 162 a/168 a. Similarly, a second collapsible chimney end wall X2 includes the chimney gusset panels 160 b, 166 b and the composite chimney end panel 162 a/168 a. According to this exemplary method, the collapsible chimney end walls X1, X2 are formed as part of the top wall 212 of the carton 200 and are positioned adjacent the outside surface of the top panel 112.

Referring to FIG. 4, the collapsed tubular structure T is in a condition which is ready for the second phase of setup, including automatic erecting, loading, folding and sealing using an automatic packaging machine or out-plant equipment (OPE), which is typically in an offsite bottling or packing facility. Those skilled in the art will be familiar with the equipment and methods for erecting, loading, and sealing a tubular structure to form a carton, so only operations specific to the embodiments described herein will be detailed.

As shown in FIG. 5, the collapsed tubular structure T is expanded to assume a three-dimensional, open-ended tubular structure T such that the primary panels define walls of the carton 200.

The collapsible chimney end walls X1, X2 are hingedly connected to the end edges of the top wall 212 and are releasably secured in a face contacting arrangement with the outer surface of the top wall 212. The composite top end flaps 164 a/170 a protrude outwardly from the end edges of the top wall 212.

In this expanded tubular form, the composite top, side, and bottom end flaps 164 a/170 a, 130 a/138 a, 134 a, 136 a can be arranged to align with a respective wall of the tubular structure T or can otherwise be folded outwardly to facilitate loading. Specifically, a portion of the bottom end flap 136 a can be folded outwardly along the fold line 198 a and the composite top end flap 164 a/170 a can also be folded outwardly.

Articles, such as cans, are loaded into the tubular structure T through one or both of the open ends of the tubular structure T. Since the collapsible chimney end walls X1, X2 are positioned against the outside surface of the top wall 212, the collapsible chimney end walls X1, X2 do not obstruct the articles as they are loaded through the open ends of the tubular structure T. Further, the collapsible chimney end walls X1, X2 do not obstruct articles even if loading is performed through one end after the other end has been closed and sealed.

After articles have been loaded into the tubular structure T, end closure structures are formed by folding the end flaps as described herein. In the exemplary embodiments, the gusset elements are configured such that one folding step causes other folds to occur simultaneously or subsequently. Each folding step can be performed automatically or manually.

Referring to FIGS. 5 and 6, according to the exemplary method, the composite top end flap 164 a/170 a is folded inwardly toward the open end of the tubular structure T along fold line 174 a/180 a. Thereafter, the first and second side end flaps 130 a/138 a, 134 a are folded inwardly toward the open end of the tubular structure T along fold lines 140 a/148 a, 144 a so as to be substantially coplanar with one another. This folding operation causes the gusset panels 184 a, 186 a to compel the bottom end flap 136 a to fold upward and inward toward the opening of the tubular structure T. The outside surfaces of the gusset panels 184 a, 186 a are folded toward the outside surfaces of side end flaps 134 a, 130 a/138 a along fold lines 190 a, 196 a. The bottom end flap 136 a is folded along fold line 146 a and the inside surfaces of the gusset panels 184 a, 186 a are folded toward the inside surfaces of the bottom end flap 136 a along fold line 192 a, 194 a, respectively. The gusset panels 184 a, 186 a are configured such that the bottom flap 136 a is automatically positioned at an acute angle relative to the plane defined by the side end flaps 134 a, 130 a/138 a when the side end flaps 134 a, 130 a/138 a are folded inwardly so as to be coplanar. The bottom end flap 136 a is folded upwardly and inwardly to overlap the composite top end flap 164 a/170 a. Thereafter, the distal edge of the bottom end flap 136 a is proximate to the fold lines 174 a/180 a, 142 a. The bottom end flap 136 a is secured to the composite top end flap 164 a/170 a and may be secured to the side end flaps 134 a, 130 a/138 a to retain the bottom end flap in the upright folded position. The open ends of the carton are thereby closed, end walls 218, 220 are defined, and the carton 200 is fully erected as illustrated in FIG. 6.

Formation of an expanded structure or chimney Y of the carton 200 may be accomplished with the exemplary operations as described herein, to provide access to articles enclosed within the carton 200 and to increase the capacity of the carton 200. The erection of the first collapsible chimney end wall X1 is described in detail and it should be understood that the erection of the second collapsible chimney end wall X2 is substantially the same and substantially simultaneous.

Referring to FIGS. 6-8, the tear strip Sa/Sb is operated to separate the chimney side panels P1, P2 from one another. The illustrated tear strip Sa/Sb is removed in two sections Sa, Sb. The tear strip section Sa is grasped at an end that is defined by the severance line C and is pulled toward the end wall 218. When the tear strip section Sa reaches the collapsible chimney end wall X1, the tear strip section Sa breaks the releasable connection between the collapsible chimney end wall X1 and the top wall 212. Alternatively, the user can detach the collapsible chimney end wall X1 from the top wall 212 and then operate the tear strip section Sa.

In the first exemplary embodiment, the tear strip section Sa is detached from the carton 200 as the tear strip section Sa reaches the fold line 142 a. However, where a carton is formed with the first exemplary method described above from blanks such as those shown in FIGS. 9 and 16, the tear strip section Sa additionally separates the chimney gusset panels 160 a, 166 a from one another. It should be understood that means for separating the chimney side panels P1, P2 and/or the chimney gusset panels 160 a, 166 a includes, but is not limited to, one or more tear strips, severance lines, rip cords, zippers, controlled separation features, combinations thereof, and the like.

Referring to FIG. 7, to further erect the chimney, the collapsible chimney end wall X1 is folded outwardly along fold lines 142 a, 174 a/180 a and away from the top wall 212, for example, so as to be substantially coplanar with the top wall 212. Once the collapsible chimney end walls are folded sufficiently outward, the chimney side panels P1, P2 are then pivoted outwardly which causes and the chimney gusset panels 160 a, 166 a to be separated along the severance line 154 a. Thereafter, the chimney gusset panels 160 a, 166 a act as gussets between the composite chimney end panel 162 a/168 a and the chimney side panels P1, P2 such that, as the chimney side panels P1, P2 are rotated outwardly to be coplanar with the side walls 210, 214, the composite chimney end panel 162 a/168 a and the chimney gusset panels 160 a, 166 a rotate so as to be substantially coplanar with one another and with the end wall 218. Specifically, the composite chimney end panel 162 a/168 a rotates inwardly along the fold line 174 a/180 a and the chimney gusset panels 160 a, 166 a rotate relative to both the composite chimney end panel 162 a/168 a along fold lines 172 a, 178 a and the chimney side panels P1, P2 along segments 142 a′, 142 a″ of the fold line 142 a.

Thereby, the carton 200 is arranged to include an expanded portion or chimney Y, as shown in FIG. 8. The chimney includes side walls defined by the chimney side panels P1, P2 and end walls defined by the expanded collapsible chimney end walls X1, X2. Generally described, the chimney Y provides an opening to the carton 200 where the height of each of the side and end walls 210, 214, 218, 220 is increased. Thus, the chimney Y increases the volume of the carton 200 such that the carton 200 is capable of receiving and retaining additional articles and/or cooling materials such as ice.

It should be noted that, in the first exemplary embodiment, the chimney Y is formed entirely from the composite top wall 212, and specifically from the chimney side panels P1, P2 and the collapsible chimney end walls X1, X2.

Second and third exemplary embodiments of the present invention are illustrated in FIGS. 9-15 and FIGS. 16-23, respectively. Blanks 300, 500 of the second and third exemplary embodiments are substantially similar to the blank 100 of the first exemplary embodiment, with the notable differences between the blanks including features for securing the collapsible chimney end walls to the carton and features that provide means for separating the chimney gusset panels 160 a, 166 a from one another. In addition, second and third exemplary methods of folding and securing the blanks 300, 500 as cartons 400, 600 illustrate alternative locations for storing the collapsible chimney end walls X1, X2. For example, the second exemplary embodiment demonstrates that the collapsible chimney end walls X1, X2 can be stowed inside the carton 400 against the top wall 212 and the third exemplary embodiment demonstrates that the collapsible chimney end walls X1, X2 can be stowed outside the carton 600 against the end walls 218, 220. It should be noted that the blanks 100, 300, 500 can be folded and secured according to the different exemplary methods described herein depending on the desired features of the carton.

For each of the first, second, and third embodiments, like references are used to identify like elements. For the second and third embodiments, elements that have already been described in detail for the first embodiment will generally not be described in further detail unless such a description is useful for understanding. Rather, the description of the second and third embodiments will focus on the unique features thereof.

Turning to FIGS. 9-15, the second exemplary embodiment is described. Referring first to FIG. 9, the blank 300 includes a tear strip Sa/Sb that extends across the top panel 112 and additionally extends across chimney end flap panel groups 132 a, 132 b such that the severance lines 128 a, 128 b extend between the voids V. Thus, the tear strip Sa/Sb functions to separate the chimney side panels P1, P2 as well as the chimney gusset panels 160 a, 166 a.

As in the first exemplary embodiments, the carton 400 (shown in FIG. 14) is formed in two phases, such that the first phase can be performed on IPE and the second phase can be performed on OPE. FIGS. 9-12 illustrate the IPE phase of pre-folding steps that are performed on the blank 300 to prepare it for the OPE phase. Notably, the folding method differs from that of the first exemplary embodiment primarily in that the chimney end flap panel groups 132 a, 132 b are folded and secured to position the collapsible chimney end walls X1, X2 against the inner surface of the top wall 212 of the carton 400.

In the IPE phase, referring to FIG. 9, adhesive is applied to the inside surface of the top panel 112 directly onto, or on either side of, the tear strip Sa/Sb. Adhesive can additionally or alternatively be applied to the inside surfaces of the chimney gusset panels 160 a, 166 a. Then, referring to FIGS. 9 and 10, the chimney end flap panel group 132 a is folded along the fold line 142 a until the inside surfaces of the chimney gusset panels 160 a, 166 a are in a face contacting arrangement with the inside surface of the top panel 112 whereby the adhesive detachably secures the chimney gusset panels 160 a, 166 a to the top panel 112.

Turning now to FIGS. 10 and 11, the second chimney end panel 168 a, along with the second top end flap panel 170 a, are folded along fold line 178 a such that the outside surface of the second chimney end panel 168 a is in a face contacting arrangement with the outside surface of the second chimney gusset panel 166 a. Adhesive, in the form of glue strip G, is applied to the outside surface of the first chimney end panel 162 a and the first top end flap panel 164 a. Additionally or alternatively, adhesive (not shown) can be applied to the inside surface of the second chimney end panel 168 a and to the second top end flap panel 170 a. As the first chimney end panel 162 a and the first top end flap panel 164 a are folded along the fold line 172 a, the top end flap panels 164 a, 170 a partially overlap and are secured to one another and the chimney end panels 162 a, 168 a partially overlap and are secured to one another. The top end flap panels 164 a, 170 a are secured to one another to define the composite top end flap 164 a/170 a and the chimney end panels 162 a, 168 a are secured together to define the composite chimney end panel 162 a/168 a. Further, the fold lines 174 a, 180 a substantially align with one another to provide the fold line 174 a/180 a that hingedly connects the composite top end flap 164 a/170 a and the composite chimney end panel 162 a/168 a. Collapsible chimney end walls X1, X2 are defined and each include a composite chimney end panel and chimney gusset panels, as described for the first embodiment.

According to this exemplary method, the blank 300 is formed as a tubular structure after the collapsible chimney end walls X1, X2 and composite top end flaps 164 a/170 a, 164 b/170 b are formed. Referring to FIGS. 11 and 12, the blank 300 is formed as a tubular structure T by folding the first side panel 118 along fold line 126 towards the inside surface of the blank 300, applying adhesive to the inside surface of the first side panel 110, and folding the blank 300 along the fold line 124 toward the inside surface of the blank 300 such that the first side panels 110, 118 overlap and are secured to one another.

It should be noted that the collapsible chimney end walls X1, X2 positioned inside of the collapsed tubular structure T, as shown in FIG. 12. One benefit of this arrangement is that the collapsible chimney end wall is not visible when the carton 400 is fully formed, as described in further detail below.

The collapsed tubular structure T now is ready for the second phase of setup, including automatic erecting, loading and sealing using a packaging machine. As shown in FIG. 13, the collapsed tubular structure T is expanded to assume a three-dimensional, open-ended configuration having a pair of collapsible chimney end walls X1, X2 that are secured to the inner surface of the top wall 212 and composite top end flaps 164 a/170 a protruding outwardly from the opposite end edges of the top wall 212. Articles, such as cans (not shown), are loaded into the tubular structure T through one or both of the open ends as described above for the first exemplary embodiment.

Referring to FIGS. 13 and 14, the end closure structures are formed by folding the end flaps as described above for the first exemplary embodiment. By this method, the opposite open ends of the tubular structure T are closed and the carton 400 is fully erected as illustrated in FIG. 14.

Formation of the expanded portion or chimney Y of the carton 400 can be accomplished with the exemplary operations as described herein, to provide access to articles enclosed within and to increase the capacity of the carton 400. Referring to FIGS. 14 and 15, the tear strip Sa/Sb is operated to separate the chimney side panels P1, P2 and to separate the chimney gusset panels 160 a, 166 a.

The illustrated tear strip Sa/Sb is removed in two sections Sa, Sb. Referring to FIG. 14, the tear strip section Sb is pulled toward the adjacent end wall 220 until the tear strip section Sb reaches the fold line 142 b. Thereby, the chimney side panels P1, P2 are separated from one another. The tear strip section Sa, Sb is then pulled back toward the opposite end wall 218 to separate the chimney gusset panels 160 b, 166 b.

Referring to FIG. 15, once each of the tear strip sections Sa, Sb are removed, the chimney side panels P1, P2 can be pivoted outwardly, with the chimney gusset panels 160 a, 166 a urging the composite chimney end panel 162 a/168 a to fold outwardly until the chimney Y is formed as shown in FIG. 15 and as described in the first embodiment.

It should be understood that, in the second exemplary embodiment, the chimney Y is formed entirely from the top wall 212, and specifically from the collapsible chimney end walls X1, X2 and the chimney side panels P1, P2.

Turning now to FIGS. 16-23, the third exemplary embodiment is described. Beginning with FIG. 16, the tear strip Sa/Sb of the blank 500 extends across the top panel 112 and across the chimney end flap panel groups 132 a, 132 b as in the second exemplary embodiment. In this embodiment, end tabs Ba, Bb are attached to opposite ends of the tear strip Sa/Sb.

Erecting the carton 600 from the blank 500 may be accomplished with the folding operations as described herein. The blank 500 can be pre-formed into a collapsed tubular structure T according to the following exemplary method. As shown in FIGS. 16 and 17, the second chimney end panel 168 a, along with the second top end flap panel 170 a, are folded along the fold line 178 a toward the inside surface of the blank 500 such that the second chimney end panel 168 a is in a face contacting arrangement with the second chimney gusset panel 166 a and the second top end flap panel 170 a is in a face contacting arrangement with the inside surface of the top panel 112. Adhesive is applied to the inside surfaces of the first chimney end panel 162 a and the first top end flap panel 164 a and alternatively or additionally to the outside surfaces of the second chimney end panel 168 a and the second top end flap panel 170 a (not shown). The first chimney end panel 162 a, along with the first top end flap panel 164 a, are folded along the fold line 172 a toward the inside surface of the blank 500 such that the overlapping portions of the first and second chimney end panels 162 a, 168 a and the first and second top end flap panels 164 a, 170 a are secured to one another resulting in composite chimney end panel 162 a/168 a and composite top end flap 164 a/170 a, which are hingedly connected to one another along a composite fold line 174 a/180 a. Collapsible chimney end walls X1, X2 are defined as above to each include a composite chimney end panel and chimney gusset panels.

As shown in FIG. 17, glue spots G are applied to the outside surfaces of the composite chimney end panel 162 a/168 a and the composite top end flap 164 a/170 a. Turning to FIGS. 17 and 18, the composite top end flap 164 a/170 a is folded along fold line 174 a/180 a into a face contacting arrangement with and is releasably secured to the composite chimney end panel 162 a/168 a.

As shown in FIGS. 18 and 19 and described in the previous embodiments, the first side panels 110, 118 are then secured together to provide a composite side wall 110/118 and to complete the formation of the collapsed tubular structure T. Thus, according to the exemplary method, the tubular structure is formed after formation of the collapsible chimney end walls and composite top end flaps.

The collapsed tubular structure T is in a condition which is ready for the second phase of setup, including erecting, loading, and sealing using an automatic packaging machine. As shown in FIG. 20, the collapsed tubular structure is expanded to assume a three-dimensional, open-ended tubular structure T having both the collapsible chimney end walls X1, X2 and the composite top end flaps 164 a/170 a, 164 b/170 b protruding outwardly from the opposite end edges of the top wall 212. It should be noted that the collapsible chimney end walls X1, X2 and the composite top end flaps 164 a/170 a, 164 b/170 b can be folded away from the open ends of the tubular structure T so as not to obstruct the opening of the tubular structure T. Further, the tubular structure T can be easily loaded through one end after the other end has been closed and sealed as the collapsible chimney end walls X1, X2 are positioned adjacent the outside surface of the end walls 218, 220.

Referring to FIGS. 20 and 21, the end closure structures of the carton 600 are formed by folding the end flaps as described herein. According to an exemplary method, the first and second side end flaps 130 a/138 a, 134 a are folded inwardly with respect to the interior of the tubular structure T and along fold lines 140 a/148 a, 144 a to be substantially coplanar with one another. This folding operation causes the gusset panels 184 a, 186 a to compel the bottom end flap 136 a to fold upward and inward toward the opening of the tubular structure T. The bottom end flap 136 a is folded additionally upwardly and inwardly until its distal edge is proximate to the fold lines 174 a/180 a, 142 a. The bottom end flap 136 a may be secured to the side end flaps 134 a, 130 a/138 a to retain the bottom end flap in the upright folded position. Such gluing, however, is optional. Then, while the bottom end flap 136 a is retained in the upright position, glue strips (not shown) are applied to the bottom end flap 136 a. As shown in FIG. 21, the collapsible chimney end wall X1, X2 and composite top end flap 164 a/170 a are together folded down onto the outside surface of the bottom end flap 136 a such that the composite top end flap 164 a/170 a and the end tab Ba are secured to the bottom end flap 136 a. Thereby, the opposite ends of the tubular structure T are closed, which results in the erected carton 600 as illustrated in FIG. 21. It should be noted that the collapsible chimney end wall X1, X2 forms part of an end wall 218, 220 and is positioned at the outside surface of the end wall 218, 220.

Formation of the expanded portion or chimney of the carton 600 may be accomplished with the exemplary operations as described herein, to provide access to articles enclosed within and to increase the capacity of the carton 600. Referring to FIGS. 21 and 22, the tear strip section Sa is operated to separate the chimney side panels P1, P2 from one another and the chimney gusset panels 160 a, 166 a from one another. The tear strip section Sa is grasped at the end defined by the severance line C and pulled toward the adjacent end wall 218. When the pulling motion reaches the end tab Ba, the tear strip section Sa is severed from the end tab Ba. Thereafter, referring to FIG. 22, the first collapsible chimney end wall X1 is separated from the composite top end flap 164 a/170 a and, referring to FIGS. 22 and 23, is folded toward the top wall 212 until the collapsible chimney end wall X1 is substantially coplanar with the top wall 212. After each tear strip section Sa, Sb is removed and each collapsible chimney end wall X1, X2 is separated from a respective composite top end flap 164 a/170 a, 164 b/170 b, the chimney side panels P1, P2 can be folded outwardly with the chimney gusset panels 160 a, 166 a urging the composite chimney end panel 162 a/168 a to pivot inwardly. Thereby, the carton 600 is arranged to include an expanded portion or chimney Y, as shown in FIG. 23 and described for the first and second embodiments.

The above-described embodiments are merely exemplary illustrations of implementations set forth for a clear understanding of the principles of the invention. Variations, modifications, and combinations may be made to the above-described embodiments without departing from the scope of the claims. All such variations, modifications, and combinations are included herein by the scope of this disclosure and the following claims. 

1. A blank for forming an expandable carton, comprising: a top panel comprising a first chimney side panel and a second chimney side panel which are separable from one another; and a first panel group hingedly connected to said first chimney side panel along a first end edge of said top panel and a second panel group hingedly connected to said second chimney side panel along said first end edge of said top panel; wherein said first panel group and said second panel group are configured to be folded and secured to form a collapsible chimney end wall without otherwise folding or securing said blank.
 2. The blank of claim 1, each of said first panel group and said second panel group comprising: a chimney gusset panel hingedly connected to a respective one of said first chimney side panel and said second chimney side panel; a chimney end panel hingedly connected to said chimney gusset panel; a top end flap panel hingedly connected to said chimney end panel; wherein said top end flap panels form a composite top end flap; said chimney end panels form a composite chimney end panel; and said composite chimney end panel and said chimney gusset panels form said collapsible chimney end wall.
 3. The blank of claim 2, further comprising: a first side panel hingedly connected to said top panel and a second side panel hingedly connected to a second side edge of said top panel; a first side end flap hingedly connected to said first side panel; a second side end flap hingedly connected to said second side panel, wherein said first side end flap is adjacent to and separable from said first panel group and said second side end flap is adjacent to and separable from said second panel group.
 4. The blank of claim 1, wherein said collapsible chimney end wall can be selectively positioned in a substantially face contacting arrangement to any one of: the inside surface of a top wall of said carton, the outside surface of a top wall of said carton, and the outside surface of the end wall of said carton.
 5. The blank of claim 1, further comprising a removable tear strip that extends substantially across said top panel to secure said first chimney side panel to said second chimney side panel.
 6. The blank of claim 5, wherein said tear strip further secures said chimney gusset panels together.
 7. A collapsed, end-loadable and expandable carton, comprising: an open ended tubular structure formed from a plurality of panels hingedly connected one to the next, a first one of said plurality of panels comprising a first chimney side panel and a second chimney side panel that are separable from one another, said first chimney side panel and said second chimney side panel, when separated, being foldable to provide side walls of a chimney; a first collapsible chimney end wall and a second collapsible chimney end wall, each hingedly connected to an opposite end edge of said first one of said plurality of panels; a first composite top end flap hingedly connected to said first collapsible chimney end wall and a second composite top end flap hingedly connected to said second collapsible chimney end wall, said first composite top end flap and said second composite top end flap each extending outwardly with respect to an open end of said tubular structure; wherein said first collapsible chimney end wall and said second collapsible chimney end wall are selectively positionable to: extend outwardly so as to be in a substantially face contacting arrangement with a respective one of said first top end flap and said second top end flap, or extend inwardly so as to be in a substantially face contacting arrangement with the outside surface of said first one of said plurality of panels.
 8. An expandable carton, comprising: a tubular structure defined by a top wall, a bottom wall, a first side wall, and a second side wall; said top wall comprising a first chimney side panel and a second chimney side panel that are separable from one another, said first chimney side panel being hingedly connected to said first side wall and said second chimney side panel being hingedly connected to said second side wall; and a first end wall and a second end wall, each closing an open end of said tubular structure; a first collapsible chimney end wall and a second collapsible chimney end wall, each being positioned adjacent the outside surface of one of said walls of said carton, each comprising: a chimney end panel hingedly connected to one of said first end wall and said second end wall; and a first chimney gusset panel and a second chimney gusset panel that are separable from one another, each connecting said chimney end panel to a respective one of said first chimney side panel and said second chimney side panel; wherein said first chimney side panel, said second chimney side panel, said first collapsible chimney end wall, and said second collapsible chimney end wall are movable to respective raised positions to define a periphery of a chimney.
 9. The carton of claim 8, wherein each of said first collapsible chimney end wall and a second collapsible chimney end wall is positioned adjacent the outside surface of said top wall.
 10. The carton of claim 8, wherein said first collapsible chimney end wall is positioned adjacent the outside surface of said first end wall and said second collapsible chimney end wall is positioned adjacent the outside surface of said second end wall.
 11. The carton of claim 8, wherein said first chimney side panel and said second chimney side panel are separable by a tear strip.
 12. The carton of claim 11, wherein said first chimney gusset panel and said second chimney gusset panel are separable from one another by said tear strip.
 13. The carton of claim 10, further comprising a tear strip, the removal of which separates said first chimney side panel from said second chimney side panel, and separates said first chimney gusset panel from said second chimney gusset panel; wherein said tear strip comprises an end tab at each of its ends, each end tab being secured to a respective one of said end walls to secure said first collapsible chimney and wall in a substantially face contacting arrangement to said first end wall and to secure said second collapsible chimney end wall in a substantially face contacting arrangement to said second end wall. 